Nitrodifluoraminoterphenyl compounds and processes

ABSTRACT

Nitrodifluoraminoterphenyl compounds having the structural formula:   WHEREIN R may be H or NO2. When R H the compound is 3,3&#39;&#39;&#39;&#39;Bis(difluoramino)-2,2&#39;&#39;&#39;&#39;,4,4&#39;&#39;,4&#39;&#39;&#39;&#39;,6,6&#39;&#39;,6&#39;&#39;&#39;&#39;-octanitro-m-terphenyl (DDONT) and when R NO2 the compound is 3,3&#39;&#39;&#39;&#39;-Bis(difluoramino)2,2&#39;&#39;,2&#39;&#39;&#39;&#39;,4,4&#39;&#39;,4&#39;&#39;&#39;&#39;,6,6&#39;&#39;,6&#39;&#39;&#39;&#39;-nonanitro-m-terphenyl (DDNONA). Procedures are described wherein diamino precursors of the indicated compounds are prepared and the final compounds are obtained by a fluorination operation. The compounds are highly energetic and suitable for use as explosives and particularly in exploding bridge wire (EBW) detonators.

United States Patent n 1 Lerom et al.

July 8,1975

[ NITRODIFLUORAMINOTERPHENYL COMPOUNDS AND PROCESSES [75] lnventors: Michael W. Lerom, Menlo Park;

Howard M. Peters, Palo Alto. both of Calif [73] Assignee: The United States of America as represented by the United States Atomic Energy Commission, Washington, DC.

221 Filed: Apr. 20, 1972 211 Appl. No.: 246,031

[52] US. Cl. 260/576; l02/70.2; 260/581;

260/6l2 R; 260/646; 260/688 [51] Int. Cl. C078 87/100 [58] Field of Search 260/576 [56] References Cited UNITED STATES PATENTS 3,751,473 8/1973 Hill ct al. 0. 260/577 Primary Examiner-R. V. Hines Attorney, Agent, or Firm-John A Horan; Frederick A. Robertson; lrene S. Croft 5 7 ABSTRACT Nitrodifluoraminoterphenyl compounds having the structural formula:

3 Claims, No Drawings NITRODIFLUORAMINOTERPHENYL COMPOUNDS AND PROCESSES BACKGROUND OF THE INVENTION The invention disclosed herein was made under or in the course of Purchase Order No. 58-5131 under Contract No. AT(29-l )-789 with the United States Atomic Energy Commission.

A number of highly energetic explosives derive their energy from nitro, e.g., 2,4,6-trinitrophenyl groups. These explosives are highly stable to impact, shock, friction. electrostatic charges, high temperatures and the like. However, most are insensitive to initiation except by strong explosive shocks produced by sensitive detonators or composite detonator assemblies and are not generally susceptible to initiation by EBW (exploding bridge wire) detonation systems. Explosive compositions including the highly energetic trinitrophenyl (nitroaromatic) moiety with its inherent advantages but which could also be sensitized to EBW initiation would be valuable additions to the available stack of explosive compositions.

In classical electrical high explosive detonator systems there is employed a fuse wire adjacent to which there is disposed a primary explosive such as mercury fulminate, lead azide, lead styphnate, or other deflagrating explosive material, in an amount sufficient to detonate a base charge of high explosive such as pentaerythritol tetranitrate (PETN), trimethylene trinitramine (RDX), tetryl or the like disposed adjacent thereto. The electrical current heats the fuse wire to the melting point igniting the sensitive primary material which then detonates the base charge producing a detonation or shock wave of sufficient magnitude to detonate a large quantity of more stable high explosive to subsequently produce most of the energy obtained in the detonation.

The primary materials employed in such classical detonators are very sensitive to mechanical shock and also to induced electrical or accumulated static charges so that extreme precautions are required to avoid inad' vertent initiation. While satisfactory for usual blasting purposes, if appropriate precautions are observed, it will be noted that a relatively long and somewhat variable time period, i.e., a millisecond or greater, with a similar time period spread, elapses on application of the electrical current until the detonator ignites. It is not possible using such detonators to obtain a precise detonation time or precise sequencing or simultaneity of detonation in multiple detonation point arrays where time factors of the order of microseconds or less is of critical importance.

One approach developed in the prior art for obviatmo /u so 4 ing the difficulties associated with the use of the classical electric detonator involves the use of an exploding bridge wire to detonate a base or booster charge directly. For example, U.S. Pat. No. 3,040,660, issued Jun. 26,1962, to Lawrence H. Johnston, discloses such a device in which a bridge wire of a few thousandths of an inch diameter and a fraction of an inch in length is arranged in proximity to a quantity of an explosive of the detonating type (PETN) ordinarily used as a base or booster as described above. Another system employing an exploding bridge wire is disclosed in US. Pat. No. 3,158,098 issued Aug. 9, 1963, to Robert S. Reith et al. Such secondary base or booster explosives are substantially insensitive to spark or shock initiation but are sufficiently sensitive to be detonated by a shock produced by an exploding bridge wire with reasonable amounts of electrical energy delivered therethrough as a short time duration fast rising pulse therethrough. This arrangement greatly improves the precision and reproducibility of the time at which an initiating detonation can be made to occur. In usual practice such an arrangement may be employed for detonating the much more insensitive and highly energetic explosives such as TNT (trinitrotoluene) and other nitrated aromatic carbon compounds which can be detonated reliably only by means of a very strong shock.

A procedure for preparing certain monophenylfluoramine-nitro compounds by the liquid phase fluorination of simple nitro-substituted nitro-phenyl compounds is disclosed in Jour. Org. Chem. 38, 1387 (1968) by C. L. Coon, M. E. Hill and D. L. Ross. In such procedure an appropriate nitro-aromatic amine dissolved in HF or acetonitrile as a solvent are fluorinated by bubbling fluorine through the solution. Such procedure is also disclosed in U.S. Pat. application Ser. No. 748,569 filed July 29, 1968 by Marion E. Hill et al., now US. Pat. No. 3,751,473 issued Aug. 7,1973.

SUMMARY OF THE INVENTION The invention relates generally to processes for producing nitrated polyaromatic hydrocarbons having difluoramino substituents and, more particularly, to processes for producing terphenyl compounds having a high proportion of nitro groups thereon together with substituents difluoramino groups in a proportion appropriate for sensitization to EBW initiation and to the novel products obtained thereby. 3 ,3 BlS(DIFLUORAMlNO)-2,2,4,4',4",6,6',6- OCTANlTRO-M-TERPHENYL (DDONT) The first compound (I) of the invention is prepared by the following sequence of reactions:

SEQUENCE (A) x No lh ocrr N0 m so -so.

Br ocn Continued lilI wherein X 2 N0 3,3"BIS(DIFLUORAMINO)- 2,2.2",4,4',4",6 6',6"NONANlTRO-M- TERPHENYL (DDNONA) The second compound (II) of the invention was prepared by the following sequence of reactions:

DESCRIPTION OF PREFERRED EMBODIMENTS 3 ,3"-BIS(DIFLUORAM INO)-2,2".4,4' ,4",6,6 ,6"- OCTAN ITRO-M-TER PH ENY L (DDON T) The first compound of the invention is prepared by reactions 2-6 shown above and described generally as follows: 4,6-dinitro-1,3-dibromobenzene (IV) is obtainable by reaction 1 as by nitration of dibromobenzene (III) using a mixture of KNO in H (96percent) (Beilstein 5, 268). As shown in reaction (3) 3- bromo-Z,4 6-trinitroanisole (Vl) is obtainable by nitration of 3-bromoanisole (V) with percent HNO in 30percent oleum (H SO $0 OCH:

X X X metal (Cu) to yield dimethoxyoctanitroterphenyl) (VII) as indicated in reaction (4). Reaction 4 may be erratic with regard to reproducible product yields. However, it is found that activation of the copper assures consistently high yields of (VII). Such activation involves the treatment of the copper with an iodinelacetone solution followed by washing with dilute hydrochloric acid an anhydrous acetone. This pretreatment of the copper undoubtedly produces trace quantities of copper iodide that are dissolved and removed by the hydrochloric acid leaving very active sites on the metal. The acetone serves to remove any traces of milling oil and moisture on the copper.

Dimethoxy-octanitroterphenyl is then aminated, as in reaction (5) by bubbling NH through a IOpercent solution thereof in lzl tetrahydrofuran: methanol solvent for about 0.5 hour. The crude product may be purified by dissolution in dimethylformamide and adding methanol to recrystallize the product, i.e., diaminooctanitroterphenyl (VIII).

Diaminooctanitroterphenyl (VIII) is then fluorinated, as in reaction 6 to yield 3,3"-Bis(difluoramino)- 2,2",4,4',4",6.6',6"-octanitro-m-terphenyl (DDONT, I). More particularly. superior fluorinating conditions comprise bubbling fluorine gas through an acetonitrile Dibromodinitro benzene (IV) is then reacted with bromotrinitroanisole (V) in the presence of copper solution of \"III at about 35C or at least below about 25C. It is necessary to bubble fluorine through the mixture until the starting material dissolves and until the color of the solution changes from dark orange to light orange. Further fluorination does not appear to affect the yield. Fluorination at or 15C or using anhydrous HF solvent gives much lower yields of product. Some impurities result due to incomplete fluorina tion and direct fluorination of the ring. Purification is accomplished as described for compound (II) and in the Examples. 3,3"-Bis(DIFLUORAMINO)- 2.2',2",4.4,4",6 6',6-NONANITRO-M- TERPHENYL (DDNONA) l.3-dibromo-2,4.6-trinitrobenzene (IX) is easily obtained by nitration of readily available mdibromobenzene using a mixture of potassium nitrate and oleum. Such compound may be coupled with bromoanisole (V) in the presence of activated copper, reaction (7), to produce 3,3"-dimethoxy-2',4'.6- trinitro-m-terphenyl (X). A preferred procedure for the preparation of dimethoxynonanitroterphenyl (XI), Reaction 9. is the treatment of (X) with potassium nitrate in 30percent -oleum overnight at ambient temperature and heating at 110C for 4 to 5 hours. (XI) in yields of -20 percent are routinely obtained. However. (XI) was also obtained in a 15 percent yield by treatment of 3,3"-dimethoxy-2,4,6-trinitro-mterphenyl (X) with 90 percent nitric acid and 30 percent oleum at 130C for 3 hours.

Because the preparation of the (XI) proceeds in low yield. a number of other methods of preparation were investigated. One synthesis attempted was the mononitration of VII to XI. Thus, VII was treated with 90 percent nitric acid and 30 percent oleum for 4 hours at 130C; only percent of the unreacted starting material was recovered. (VIII) was also treated with KNO SO mixture at 130C for 4 hours; again, only starting material was recovered. Finally, (VII) was treated with nitronium tetrafluoroborate in tetramethylene sulfone for 1 hour at 95C, and 50 percent of the starting material was recovered. Therefore, we concluded that the central benzene ring was deactivated by the nitro groups, and the 2'-position was sterically hindered by the flanking phenyl groups, which made the nitration of VII to XI very difficult.

Two additional factors affect the synthesis of XI by nitration procedures. First, as the nitration proceeds, the polynitroterphenyl product becomes more insoluble in the nitrating medium. This is especially true with potassium nitrate-oleum mixtures. In addition, foaming is a severe problem at the higher temperatures (I 10l 30C). Second, the nitrating reagents used were also strong oxidizing agents. Since the methoxy groups oxidize readily to hydroxyl, their desired functionality are easily destroyed. 3,3"diamino 2,2',2,4,4,4",6,6',6"-nonanitroterphenyl (XII) is prepared by dissolving XI in a tetrahydrofuran/methanol/dimethylformamide (50:2022 retrorespectively) solution and bubbling anhydrous ammonia therethrough at ambient temperature as shown in reaction 10. Compound (XII) is then fluorinated preferably by suspension in acetonitrile, flushed with nitrogen, and cooled to about 35C. A mixture of percent fluorine with nitrogen is bubbled through the suspension for about 6 hours, the solution is flushed with nitrogen and diluted with methylene chloride and stireed overnight with M,,SO to eliminate HF. The mixture is then evaporated to yield a crude product gum from which the product can be extracted with ethyl acetate. which is evaporated and the residue purified on a silica gel column by elution with ethyl acetate.

Further details of the processes and products of the invention will be set forth in the following illustrative examples:

EXAMPLE I Relevant to reaction sequence (A) 1,3-Dibromo-2.4.6-trinitrobenzene, IV [reaction (a)] Dry potassium nitrate, 92.2 grams (0.83 mole) was added portionwise during 20 minutes to 42.4 grams of 30 percent oleum (1.66 mole of S0 A resulting exotherm raised the temperature of the mixture to C. With rapid stirring ofthis nitration mixture, 21.8 grams (0.092 mole) of m-dibromobenzene was added dropwise during 15 minutes at 120C. A mild exotherm was observed during the addition; however, it was necessary to warm the reaction mixture with an oil bath to maintain a 120I30C temperature range. After the addition was complete, the mixture was stirred for 4 hours at C, was cooled to 10C, and was slowly quenched on 700 grams of crushed ice. The resulting aqueous mixture was extracted with four 300-ml portions of methylene chloride, the extracts were combined, and then washed with two 500-ml portions of brine. The organic phase was filtered through anhydrous sodium sulfate and evaporated to give 32.3 grams (95 percent) of crude product as a yellow powder Recrystallization of the yellow powder from 90 ml ofchloroform gave 23.4 grams of Compound IV (69 percent) as yellow prisms, m.p. I36I37C, lit. (2) mp C.

3,3-Dimethoxy-2,2",4,4',4",6,6',6"-octanitro-mterphenyl, VII [reaction (4)] Activated copper powder (21.5 grams, 034 gramatoms, Venus 44-F) in 50 ml of nitrobenzene was heated to 125C. A solution of l,3-dibromo-4,6- dinitrobenzene (15.9 grams, 0.049 mole). 3-bromo- 2,4,6-trinitroanisole (39.3 grams, 0.012 mole) and warm nitrobenzene (100 ml) was added in three portions. After the first 25-m1 addition, no temperature rise was observed, and the slurry was warmed to 135C. With the second 25-ml addition, an exothermic reaction occurred and the temperature rose to 144C. The metallic copper slowly took on a grey-brown color as copper bromide was formed. The remaining solution was added over 20 minutes at l35-I40C and the slurry was stirred an additional 30 minutes at 135C. The mixture was cooled to 60C and filtered into a 1- liter, 3-necked flask. The nitrobenzene was removed by steam distillation: this operation required approximately 5 hours. The yellow distillate was discarded, and the aqueous phase was decanted from the crude residual product, a dark gum. The gum was washed well with water, dissolved in 500 ml of boiling acetone, and treated with activated charcoal (Norit). The charcoal was removed, washed well with acetone, and the combined filtrates concentrated to about 250 ml using reduced pressure. Hot methanol (500 ml) was added. and the solution was allowed to cool. A combined total of 16.8 grams (53 percent yield) crystalline VII was obtained from the first crystallization and from the mother liquors, m.p. 267-270C, reported (13) mp 265C.

3.3"-Diamino-2,2".4,4',4",6.6,6"-octanitro-mlmpure I (1.1 grams. m.p. 2022(l4C dec.) was terphenyl. VIII {reaction 5] chromatographed again on a silica gel column (15 grams. 1.1 cm. i.d.) loaded and eluted with l percent pentane/ benzene. Fractions of 5. 50, and I50 ml were collected. Fraction 3 gave a good TMPDA spot test and on evaporation produced a yellow solid which was recrystallized from ethyl acetate/chloroform, 0.030 grams (2 percent yield); m.p. 239C (dec.); IR (nujol and fluorolube) 3010 (w. aromatic CH). I580 (m. aro- 10 matic CH), I540 (s. CNO and I340 cm. (s, CNO- NMR 69.41 (complex m. 3,5,5',5"-protons). 8.28 (s,l.2'-proton). 62.3 (d. J 20.3 Hz. 3.3"-

Compound VII (11.0 grams, 0.0l7 mole) was dissolved in I I0 ml of 1/! tetrahydrofuran/methanol and treated with a slow stream of anhydrous ammonia for 0.5 hour with no external cooling. The yellow solution turned a red-orange color within one minute and an increase in temperature was observed (-C). Metha nol (100 ml) was added and the solution was carefully heated to boiling to remove excess ammonia. After cooling, 8.4 grams (80 percent crude yield) of VIII as a yellow product was obtained which was recrystallized by dissolving in 37 ml of hot dimethylformamide and adding methanol 15 ml). The yellow powder. VIII, 6.3 grams (60 percent) exploded at 352C. reported (5 m.p. 355C (exp).

Anal. Calc. for

3; 0. F. 10.93; N. 20.23 octanitro-m-terphenyl. I (DDONT) [reaction (6)] H. 58: H. 0.77: F. 10.60; N. I9.ll

A. Pr%pertieslofD ,3"-B1s (difluoramino)-2,2", l, l', l",6,6',6"-octan1t;ro-

. m /R\ ma Structure: F 11 0 0 O 1 m m3 I 0| To a 360-ml Kel-F reactor was added VIII (5.0 a f f w m f 'l H lNnflmFi grams, 0.087 mole) and anhydrous Nanograde acetonig zt s m 21m powder trile (250ml). The resulting yellow suspension was Crystal Density: 1.75 cooled to -C, using a Dry Ice/ethylene dichloride Analyses M Fmmd bath and was flushed with nitrogen 100 ml/min for 15 C min). Gaseous fluorine diluted with nitrogen was bub- 35 H 0.58 0.77 bled through the stirred mixture for 5 hours (20 per- F 10.98 urn cent F in N at I20 ml/min). The exit gases were N 20,23 9, vented through concentrated KI/water solution to de- 8 ,X, t H d DDONT b M ens! tvi 0 an m 1 a t stroy the excess fluorine. The suspension changed from 40 I g sensitive sg a fl g lfi Z yellow to red-orange to clear orange to yellow during the reaction. After 5 hours, the fluorine was discontin- Exploding Bridge ued and toxic gases (F HF. and fluormated CH CN) Wire Test:

were flushed from the Kel-F vessel with nitrogen (I20 DDONT can be easily handled with the usual precautions.

210 I 222 PETN: I84 I,, 197 Nmr (Acetone-d References, TMS. CFCI ml/min for 15 min). Shift Assignment 1,; The yellow solution was filtered to remove unreacted 0 59 multiple VIII and methylene chloride (250 ml) and anhydrous 1 1.72 singlet 2'-proton magnesium sulfate grams) were added to the fildoublet trate. After stirring for l hour the solution was filtered and evaporated carefully using a water bath to dryness 5O EXAMPLE under reduced pressure. The crude yellow I was dissolved in hot ethyl acetate (-20 ml). filtered. and concentrated to an oil (6-8 ml). The oil was chromato- 3,3"Dimeth0Xy-2',4,fi'trinitro-m-terphenyl. X [Regraphed on a silica gel column (I25 grams. 2.6 cm) action (7)] loaded with a 50 percent benzene/hexane solution and A modified Ullman procedure was used. meluted with ID percent ethyl acetate/benzene. Frac- Bromoanisole (187 grams, l mole) and 1,3-dibromotions of I25. I25. I25. 250. 25. I25. and 50 ml were 2.4,6-trinitrobenzene (24 grams, 0.065 mole) were collected; I moved down the column as a red band and combined and slowly heated to 80C. A yellow solution was collected as Fraction 6. which gave a good spot test resulted. Activated copper (25 grams; 0.40 gram for NF with TMPDA reagent (purple yellow with atom) was added in S-gram portions over a 25-minute heating). Upon evaporation, Fraction 6 gave 3.0 grams period. while raising the temperature slowly from of yellow Crude I that exploded at m.p. 202204C to C. Within 15 minutes, an exotherm of 8C and (dec.). TLC analysis (silica gel, 5 percent ethyl acetaproduction of copper bromide were observed. The gray te/benzene. developed with UV and TMPDA indicated slurry was heated at l25-l 30C for 2.5 hours. cooled. three components. R, 0.I4 (streak), R, 0.32, and Rf 65 and filtered to remove the unreacted copper and cop- 0.46. Preparative TLC using silica gel produced impure per bromides. The precipitate was washed with ISO ml I(l,l grams); R, 0.46; m.p. 204C (dec). of acetone and 25 ml of benzene. The filtrates and Relevant to reaction sequence (B) washings were combined; the acetone and benzene were evaporated under reduced pressure. Unreacted m-bromoanisole amounting to 154 grams was distilled from the crude product at 4550C (0.5 mm.). Crude black residue, 30 grams (l percent yield), was dissolved in 500 ml of hot, anhydrous acetone and treated twice with decolorizing carbon [0 grams). The resulting clear brown solution was concentrated to about 200 ml and 300 ml of hot methanol was added. On cooling, an off-white powder was recovered, l5.3 grams (55 percent yield) with a melting point of l72l75C. Reported melting point is [78C, (dec.); lR (fluorolube and nujol) 3030 (w. aromatic CH), 2950 (CH O), [550 (m, CNO and i350 cm." (w, CNO

Anal. Calcd. for C,,,H, ,N,o..= C. 56.48; H, 3.55, N, 9.88. Found: C, 56.55; H, 3.63; N. 9.73.

3,3' DimethOXy-22'J", terphenyl, Xl [Reaction (a)] The nitration mixture was prepared in a 2-liter, 3- necked flask by adding 15] grams 1.5 mole) ofdry potassium nitrate incrementally over 30 minutes to 800 grams of 30 percent oleum (3.0 mole of 50 The resulting exothermic reaction raised the temperature to 70C. Potassium sulfate precipitated as the mixture was cooled to ambient temperature. After X l2.75 grams, 0.30 mole) was added quickly producing a temperature rise of 8C, the slurry was cooled and stirred for 16 hours at 27C. The slurry was then heated at 1l0l [3C for 4 hours (at this temperature foaming became severe), cooled to about 40C, and slowly quenched in l,500 grams ice. The resulting brown aqueous solution was extracted with ethyl acetate (5 X 200 ml) and the extracts were combined, washed with water (2 X 100 ml), and dried over anhydrous magnesium sulfate. The solvent was evaporated to give 5.2 grams (25 percent) as an off-white powder. Recrystallization of the crude solid from A acetone/methanol gave 4.0 grams of XI as yellow needles; mp. 3l0C, (dec.)z lR (fluorolube and nujol) 3100 (w, aromatic CH); l540 (m, CNO 1340 cm. (m, CNO NMR (dimethylsulfoxide-d 63.94 (s, 6, CH O), 8.90 (s, 2, 5,S"-protons), 9.22 (s, l.5-protons).

Anal. Calcd. for C H N O C, 346: Found: C, 34.5;

3,3"-Diamino-2,2',2",4,4',4",6,6',6"-nonanitro-mterphenyl, Xll [Reaction (l0 )1 Compound XI (1.25 grams, 1.8 mole) was dissolved in 72 ml of a tetrahydrofuran/methanol/dimethylformamide (50/20/2-v/v/v). The solution was saturated with anhydrous ammonia and stirred for 30 minutes. The solution turned from a yellow to a blood-red within a few minutes and a temperature rise of C was ob served. The solvents were removed with reduced pressure. Methanol (50 ml) was added and the slurrry was cooled and filtered. The wet, crude product, l.3 grams, was recrystallized by dissolving in 5 ml of hot dimethylformamide and adding 50 ml of hot methanol. On cooling, the yellow powder, Xll, that was recovered by filtration exploded at 355C, 0.80 grams (66 percent 10 yield); lR (fluorolube and nujol) 3400 (2,NH 3l00 (w, aromatic CH), I360 cm. (in, CNO MR (dimethylsulfoxide-d 88.74 (broad s, NH 9.l2 (s, 2, 5,5"-protons)', 0.42 (s, l,5'-protons).

Anal. Calcd. for C,,,H H,,O,,,: C, 32.50; Found: C. 33.98;

The NMR spectrum also indicated the presence of a small amount of dimethylformamide. This solvent which could not be removed by repeated drying with heat and vacuum, caused the inaccurate elemental analysis.

3.3 "-Bis(difl uoramino)-- ',4",6,6',6"-nonanitro-mterphenyl,II/( DDNONA) [Reaction(l 1)] To a 325-ml Kel-F reactor was added XII (1.5 grams, 0.033 mole) and anhydrous Nanograde acetonitrile (300 ml). The resulting yellow suspension was cooled to 35C using a Dry Ice/ethylene dichloride bath and was flushed with nitrogen ([00 ml/min for l5 min). Gaseous fluorine diluted with nitrogen was bubbled through the stirred mixture for 4 hours (20 percent F in N at ml/min). The exit gases were vented through a 2-foot column of charcoal briquettes to destroy the excess fluorine. The suspenion changed from yellow to red-orange to clear orange to yellow during the reaction. After 4 hours, the fluorine was discontinued and toxic gases (F HF, and fluorinated CH CN) were flushed from the vessel with nitrogen (120 ml/min for IS min).

The yellow solution was filtered to remove unreacted Xll and methylene chloride (200 ml), anhydrous magnesium sulfate (10 grams), and silica gel (10 grams) were added to the filtrate. After stirring for 1 hour, the solution was filtered and evaporated to dryness under reduced pressure. Crude brown II was dissolved in hot ethyl acetate (-20 ml), filtered, and concentrated to an oil [-2 ml). The oil was chromatographed on a silica gel column (ll mm. id x 30 cc.) loaded with a 50 percent benzene/petroleum ether solution and eluted with ID percent ethyl acetate/benzene. Fractions of 50, 90, 80, 100, and l50 ml were collected; ll moved down the column as a red band and was collected as Fraction 2, which gave a good spot test for NF with TMPDA reagent (purple yellow, with heating). On evaporation, Fraction 2 gave 1.0 grams of a brown gum that darkened at 250C, but did not melt. TLC analysis (silica gel, 5 percent ethyl acetate/benzene, developed with UV and IMPDA indicated one major component at R; 0.53.

lmpure II was recrystallized from ethyl acetate/benzene, giving 0.06 grams of a yellow solid, mp. 240C (dec.). After Fraction 3 was chromatographed again additional ll, 0.04 grams was obtained, mp 235C (dec.)zlR (fluorolube and nujol) 3200 (w, aromatic CH), 1600 (m, aromatic CH), 1540 (s, CNO and l340 cm. (s, CNO NMR (acetone-d 89.60 (s, l, 5'-protons), 9.55 (s, 2, 5',5"-protons) 41162.2 (5, 3,3"- NF 1 l 12 Properties of DDNONA Table III Density 'IGA OF DDNONA Th6 density f DDNONA was determined with a Time. min Temp. "C Wt. mg Total Wt Loss. mg Fischer-Davidson gravitometer by the flotation U m0 method. I50 m0 0 I52 8.80 0 I75 s73 0.02 l9l s 76 0.04 205 s 70 0.10 Run Densit 209 8.65 0. l 5 I HHS 10 x0 3.12 8.50 0.30 2 L812 83 :40 s]: 0.48 3 1.805 A\' l.8ll x4 :43 8.20 0.60 85 245 I0 0.20 8.60

c iothcrm 00 :50 0.20 8.60

. l I00 288 0.20 8.60 EBW Sensmvlll I5 I04 300 0.30 8.60

DDNONA, mp 233235C. was dried for 20 hr at 0.01 to 0.03-mm arti- 77 9 02 mm) and ground to p At 243C and 84 mm, the sample gassed off. leaving cle sIze. Headers were loaded with 71 to 86 mg of O 0.20 mg of carbon powder. A 10 C exotherm was ob- DDNQNA' whlch was equivalent to 45 to 55 percent s rv d between 84 and 85 min but returned to base of the crystal density in the packed header. PETN. den s 6 sity 1.77. was ground to 0.0l to 0.03-mm particle size D and loaded at 45 to 55 percent of crystal density Dlfferfimlall Thermal An ly i l (69 S4 lg/header) The EBW test i are gwen m The dta of DDNONA was run on a l.()-mg sample in Table The burst amperage relauve to PETN was 25 aluminum under a nitrogen flow of 15 ml/min and at las follows: 0C/min. The sample showed a broad endotherm peaking at 230C followed immediately by a broad exoo 1 o PETN 93 I" 94 therm peaking at 260 C. Above L60 C. the sample con DDNONA l,, tmuously lost weight.

DDNONA EBW TESTS Burst Amperage Scope Scope Delay Run Com- Detonation A B Voltage usec Wt, mg 706 pound I PETN yes 199 I94 700 2.5 76.3 49.7 2 PETN no I85 I84 675 2.5 79.2 5l.6 3 DDNONA yes 236 224 775 I.'] 70.5 45.4 4 DDNONA yes I91 I94 700 2.5 77.0 49.0 5 DDNONA no I83 I85 675 2.5 77.5 50.5 6 DDNONA yes I93 I90 686 2.5 76.6 48.8 7 PETN DO 192 193 686 2.5 74.2 48.3

Scope B more accurate Ihun Scope A.

=l.ow order. Header not broken. All other detonaiions resulted in fragmentation of header.

Impact Sensitivity The impact sensitivity of DDNONA was determined using a Technoproducts drop-weight tester. Values given are the 50 percent point in cm for a 3-kg and a 2-kg weight.

HMX ll-l2/3 kg. 29-30/2 kg PETN 1344/3 kg. 45/: kg DDNONA H] kg. 2-3/2 kg Spark Sensitivity.

PbN l0 millijoules. negative. 3 trials 15 millijoules. positive. 3 trials DDNONA 75 millijoules. negative. 3 trials Melting points reported are uncorrected and were obtained in a capillary using a Mel-temp melting point apparatus. Elemental analyses were determined by Stanford University and by Miss E. McCarthy, SRl Analytical Services. NMR data were obtained by Mrs. L. Stietzel using a Varian HA-IOO NMR spectrometer. Values for H Chemical shifts are given in 5 units with respect to tetramethylsilane as internal reference, and values for the 19F chemical shifts are given in (b units (7) with respect to trichlorofluoromethane as an internal reference. In NMR descriptions, s singlet, d doublet, r triplet. q quadruplet, m multiplet. Infrared spectra were run on a Perkin-Elmer Model I37 lnfracord spectrophotometer. ln lR descriptions, s strong, in medium. w weak. and b broad.

Thin-layer chromatography was carried out on Eastman Chromagram sheets of silica gel with fluorescent indicator. Anhydrous magnesium sulfate was added to reaction mixtures from fluorinations in acetonitrile to remove residual hydrogen fluoride. Since magnesium sulfate was slightly soluble in acetonitrile. addition of methylene chloride to the acetonitrile solution reduced this solubility. To remove the small amount of magnesium sulfate that dissoved, from the isolated crude product of the fluorination, the product was dissolved in methylene chloride or ethyl acetate and filtered. Elution of difluoraminonitroaromatic compounds in col umn chromatography was detected by spraying a spot of the eluate on filter paper with a 0.2 percent solution of N.N.N',N tetramethyl-p-phenylenediamine dihydrochloride in 50 percent methylene chloride and ethanol (TMPDA reagent); thin-layer chromatograms were also sprayed with TMPDA reagent. TMPDA reagent turned blue in the presence of strong oxidizers such as NF -nitroaromatic compounds. Often the blue color changed to yellow at or above ambient temperature. Densities were determined using a Fisher-Davidson gravitometer.

Caution The difluoraminonitroaromatic compounds described in this paper are explosives and sensitive to initiation by impact, shock, friction, or other means. Many difluoramino and nitroaromatic compounds are toxic in varying degrees and will cause stains and burns when brought into contact with the skin.

Exploding Bridge Wire Apparatus and Procedure pressed to a density in the range of 45 to 55 percent of the crystal density of the compound. All samples were ground in SO-mg portions with a mortar and pestle; gloves and a protective shield were used for this operation. The sample particle size (0.01 to 0.03 mm) was determined microscopically with a micrometer having a 2-mm line graduated to 0.0l mm divisions. Criteria used to identify a detonation were the sound of the explosion and the appearance of the brass fragments from the bushing. PETN (military specifications) was used as a standard. The burst amerage was determined at the time of maximum voltage across the wire.

While there has been described in the foregoing what may be considered to be preferred embodiments of the inventions. modifications may be made therein without departing from the teachings of the invention and it is intended to cover all such as fall within the scope of the appended claims.

What we claim is:

l. A nitrodifluoraminoterphenyl compound having the formula NO2 R N02 PEN NFQ O N C) O N O O N NO wherein R is a radical selected from the group consisting of H and N0 2. The compound 3.3"-Bis(difluoramino)- 2,2",4,4,4",6,6,6"-octanitro-m-terphenyl.

3. The compound 3,3'-Bis(difluoramino)- 2,2,2",4,4',4",6,6',6"-nonanitro-m-terphenyl. 

1. A NITRODIFLUORAMINOTEPHENYL COMPOUND HAVING THE FORMULA
 2. The compound 3,3''''-Bis(difluoramino)-2,2'''',4,4'',4'''',6,6'',6''''-octanitro-m-terphenyl.
 3. The compound 3,3''-Bis(difluoramino)-2,2'',2'''',4,4'',4'''',6,6'', 6''''-nonanitro-m-terphenyl. 